BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:A New Formulation of Analytic\, Non-Perturbative\, Gauge-and Loren
tz-Invariant QCD
DTSTART;VALUE=DATE-TIME:20110809T185000Z
DTEND;VALUE=DATE-TIME:20110809T191000Z
DTSTAMP;VALUE=DATE-TIME:20210624T225100Z
UID:indico-contribution-1350996@indico.cern.ch
DESCRIPTION:Speakers: Herbert Fried (Brown University)\, Thierry Grandou (
Universite de Nice)\, Yves Gabellini (Universite de Nice)\, Ming Sheu (BEA
Systems)\nA simple and previously overlooked choice of one parameter allo
ws the Schwinger/Symanzik Generating Functional of QCD to be re-written in
a manifestly gauge-invariant fashion\, without the need of Fadeev-Popov i
nsertions. When combined with Fradkin functional representations for the G
reen's function\, G[A]\, of a quark in an effective color potential A\, an
d the vacuum loop functional L[A]\, all QCD correlation functions can be r
epresented as Gaussian\, functional-linkage operations connecting relevant
combinations of G[A] and L[A]. And because the Fradkin representations fo
r those functionals are Gaussian in their dependence on A\, the functional
-linkage operation can be done exactly\, and one then sees that gauge inva
riance here is achieved by gauge-independence\, as the gauge-dependent glu
on propagators exactly cancel out everywhere. In this way\, the non-pertur
bative sums over Feynman graphs reduce to an explicit\, gauge-independent
functional expression.\n\n That new\, final functional expression now
displays a new property we call "Effective Locality" (EL)\, in which the i
nfinite sum over infinite classes of Feynman graphs corresponds to the exc
hange of a well-defined "gluon bundle" from specific space-time points on
interacting quarks and/or antiquarks. And one then sees that it is no long
er possible to continue to treat quarks as ordinary particles\, with well
defined asymptotic momenta or positions\, for they are bound objects whose
transverse coordinates can never be measured exactly. Once this necessity
of introducing realistic "transverse imprecision" is realized\, and intro
duced into the fundamental Lagrangian\, all functional sums become well-de
fined\, and one has an analytic way of obtaining physical information.\n\n
It should be noted that such progress is possible because the Fradkin
representations are Potential Theory constructs\, with reasonable approxi
mations in different physical situations\; e.g.\, at high energies\, G[A]
simplifies to a Bloch-Nordsieck/eikonal form. With those simplifications\,
and the remarkable property of EL\, we have been able to calculate eikona
l amplitudes for quark-antiquark scattering\, and for three-quark scatteri
ng\, and to extract from these eikonal functions the form of binding poten
tials that produce hadrons. And\, most interesting\, for the first time we
can exhibit a mechanism which leads to effective Yukawa scattering betwee
n nucleons\, including a scattering potential which becomes negative\, as
needed to make a deuteron from a proton and a neutron. This\, to our knowl
edge\, and for the first time ever\, is Nuclear Physics from basic\, reali
stic QCD.\n\n This work\, by myself (HMF)\, French colleagues Grandou
and Gabellini (of the Universite de Nice)\, and my ex-Brown student Ming S
heu\, is barely 18 months old at this writing\; and there are many problem
s remaining to be studied\, such as non-perturbative renormalization theor
y\, the quark-gluon plasma\, and - indeed - all of Nuclear Physics. On the
basis of what we have been able to derive up to this point\, we believe t
hat this approach to analytic QCD calculations will\, in the future\, beco
me extremely useful. It should be noted that the above remarks are a descr
iption of "textbook" QCD\, with one type of quark and the massless gluons
of SU(3)\; flavors and electroweak effects\, as well as spin and angular m
omentum dependences are to be added in later on.\nhttps://indico.cern.ch/e
vent/129980/contributions/1350996/
LOCATION:551 A (Rhode Island Convention Center)
RELATED-TO:indico-event-129980@indico.cern.ch
URL:https://indico.cern.ch/event/129980/contributions/1350996/
END:VEVENT
END:VCALENDAR